For centuries, cannabis has been known to stimulate the appetite, and it’s use for this reaction is documented in many different cultures throughout the world. Ancient Chinese records dating back to 2700 B.C. describe the use of marijuana tea to increase hunger, and practitioners of traditional Ayurvedic medicine in India show similar documentation.
In more recent times, this marijuana induced hunger has been dubbed the munchies. Although some users who do not need help eating may see this as an adverse side effect, it is actually extremely beneficial for many people suffering from a variety of medical conditions. Previous research concluded that tetrahydrocannabinol (THC) increased olfactory sensitivity, which thereby stimulated the appetite because food smelled and tasted better. This still may play a significant role, but it is no longer the sole factor.
The neurological stimuli behind feeling hungry, even when sated, after consuming marijuana has not been pinpointed until now.
The new study by Yale School of Medicine researches, titled “Neuroscience: A cellular basis for the munchies,” was published in the February 18 issue of the journal Nature. The research is part of a larger effort to understand how the brain controls a person’s appetite.
The findings of the study came as a surprise to the research team because the cause of the appetite stimulation resides within the same neurons that are known to produce the feeling of being full, which under normal circumstances effectively suppress the appetite.
The pro-opiomelanocortin (POMC) are neurons located within the hypothalamus. The hypothalamus acts as the body’s homeostasis headquarters in the brain. Under normal circumstances, the POMC work to suppress appetite because when the POMC fire, it causes the body to produce a hormone called α-melanocyte (α-MSH). The α-MSH then signals the body to stop eating by sending the feeling of being full.
After cannabinoids are introduced:
This study discovered that when cannabinoids are introduced to the body, it causes the POMC to work backwards. Instead of signaling the α-MSH to produce feelings of satiery, the POMC send signals of hunger that result in an increased appetite and the need to eat.
Tamas Horvath, the lead author in this study, is a professor of neurobiology and director of the Yale Program in Cell Signaling and Neurobiology of Metabolism. Horvath explained his feelings of surprise,
“By observing how the appetite center of the brain responds to marijuana, we were able to see what drives the hunger brought about by cannabis and how that same mechanism, that normally turns off feeding, becomes a driver of eating,”
“It’s like pressing a car’s brakes and accelerating instead. We were surprised to find that the neurons we thought were responsible for shutting down eating, were suddenly being activated and promoting hunger, even when you are full. It fools the brain’s central feeding system.”
The original goal of the research was to “monitor the brain circuitry that promotes eating by selectively manipulating the cellular pathway that mediates marijuana’s action on the brain, using transgenic mice.”
Now that this information has been discovered, it has the ability to open doors to a whole new world of appetite stimulation for patients suffering from conditions like cancer, HIV/AIDS and others patients who’s traditional treatment regimen results in difficulty eating. Patients need to be able to eat to replenish the body’s energy source, which will give the immune system the strength to go on fighting. This also has the potential to help those suffering from anorexia and cachexia.
More research will need to be done on the subject to validate all findings, but this new development shows even more potential for medical cannabis as a viable addition to the treatment plans of patients suffering from a variety of debilitating medical conditions which include a loss of appetite as a symptom.
This post was originally published on February 18, 2015, it was updated on October 5, 2017.